Windows XP will be getting even less secure next year, when Google stops updating Chrome for users of Microsoft's nearly geriatric operating system.

The company announced today that PCs running XP and Vista will be able to keep using Chrome after April 2016, but Google will cease providing updates to its browser, including security-focused patches. That same deal goes for Mac users running OS 10.6, 10.7 and 10.8.

Google said it was turning off the updates because the makers of all five OSs had stopped providing official support for them.

"Such older platforms are missing critical security updates and have a greater potential to be infected by viruses and malware," Chrome Director of Engineering Mark Pawliger said in a blog post announcing the decision.

Google said earlier this year that it planned to stop supporting old operating systems, and called out XP in particular as a problem. Microsoft's operating system, while more than a decade old, is still clinging to life on computers in homes and organizations large and small. Microsoft ended support for XP last year, but some organizations (including the U.S. Navy) haven't completely made the jump yet.

This is also bad news for people who want to keep old Intel Macs limping along with new versions of Chrome. Google didn’t provide a version of its browser for older computers using PowerPC processors, which are stuck on OS 10.6.8, but other computers including the mid- and late-2006 editions of the iMac can’t upgrade to a supported operating system.

It's a tough spot to be in, but come April, there won't be much of a choice for those people who want their old computer to still have a secure version of Chrome. Either they update their hardware, or they get left behind.

This story has been updated at paragraph six to correct Google Chrome’s availability for PowerPC Macs.